(a) Technical Field of the Invention
The present invention generally relates to thermal therapy devices, and more particularly to a handheld thermal therapy device using internal burning to produce heat.
(b) Description of the Prior Art
Thermal treatment is a common therapy practice in which a heat source is applied to human body so that the heat is conducted to the muscle via skin tissues to relieve sore and pain, or to improve local blood circulation.
Thermal treatment could be conducted using various kinds of heat sources such as hot towels, thermal pads using chemicals, electrical heaters, or even torches. One popular thermal therapy device is a portable one with an internal burning mechanism that could be used without time and place limitations. FIG. 1 is a perspective view showing the various parts of such a conventional thermal therapy device. As illustrated, the thermal therapy device 1 mainly contains a lower tubular member 11, an upper tubular member 12, a spring 13, and a push rod 14.
The lower tubular member 11 contains a lower section 111 and an upper section 112 which are screwed together. The lower part of the lower section 111 is configured with bulges with elongated openings.
The upper tubular member 12 also contains a lower section 121 and an upper section 122 which are screwed together. In the middle of the lower section 121, an oval-shaped indentation is configured having an opening at its lower part covered by an extended blade.
The push rod 14 is installed inside the upper tubular member 12 which, in turn, is threaded through the spring 13 and inserted into the lower tubular member 11. When in use, a burnable fuel source is fixed between the oval-shaped indentation and the extended blade, and is ignited. As the fuel source is burned, the heat produced is conducted to the human body via the wall of the lower tubular member 11. This conventional design has a number of disadvantages. For example, the air circulation is usually poorly designed and the burning of the fuel source as such is easily extinguished. The conventional device also has no heat storage capacity and the produced heat is dissipated too quickly when used in an environment with strong air flow.